Extruded clay or ceramic tile, sometimes called quarry tile, is used in restaurant kitchens. Quarry tile is popular in restaurants and other kitchen areas because it is relatively inexpensive, durable, and has relatively low porosity. Quarry tile is made from natural clays with the composition being approximately 50% hard particles (silicon) and 50% soft particles (clay components). When the clay tile is fired, it develops a pervious glaze-like coating which encapsulates pores under the surface. Because of the pervious nature of the surface, these pores collect and entrap various soils that are extremely difficult to clean thoroughly.
The surface of the tile is subject to wear, polishing and soil build-up which can result in a slippery floor condition. Slippery floors result in accidents and injuries from slipping and falling. These accidents can cause a serious injury to the restaurant worker, and they result in significant costs for the restaurant owner.
One of every twenty workplace injuries in the United States occurs in a restaurant. The U.S. Food Service Industry spends approximately four hundred million dollars per year on slips and falls. Approximately half of that amount is spent on re-training and time lost, and the other half is spent on medical, worker's compensation, and overtime expenses. Many other accidents occur in hotels, homes, places of business, hospitals, and around swimming pools, due to slipping on wet surfaces of ceramic tile, glazed porcelain and smooth concrete.
During the manufacturing process of quarry tile, a natural surface roughness is created consisting of hard, microscopic peaks of silica and inert clays. The surface texture or roughness coupled with the surface porosity provides the tile with an optimum static coefficient of friction (traction). New quarry tile tends to be slip-resistant, and some tiles feature anti-slip properties such as added grit, grid patterns or a rougher surface texture. However, even the anti-slip tiles become worn, soiled, and slippery over time. After a short time, the quarry tile is subjected to abrasion and surface wear due to foot traffic, soils and daily surface cleaning. The original hard microscopic peaks become polished or worn down, leading to flat surface areas. These worn areas result in a lower static coefficient of friction and create a potentially slippery floor surface. In addition, frying, grilling and sauteing create airborne grease, which causes a potentially hazardous film to develop on kitchen floors. The grease gets carried by shoes to other parts of the restaurant. This layer of grease can be enough to cause an accident. If poorly cleaned, a quarry tile floor can become saturated with grease, and may continue to stay slippery despite routine cleaning.
To address this slipperiness problem, several techniques have been utilized. One technique is the application of an acid etchant to the surface of the floor. An example of this process is the Gillice patent, U.S. Pat. No. 3,847,688. The acid etch system works by dissolving silicon and creating microscopic pores in the tile. While the acid etchant reduces floor slipperiness on a temporary basis, it is not effective over the long-term. After use of the acid etch technique, the microscopic pores become filled with grease and other types of soil, thereby resulting in a slippery floor condition. Additionally, the acid etch process destroys the hard components of the clay tiles (the silicon), leaving softer components of the floor at the surface. These softer components are easily worn away, which can result in a worn and/or uneven floor surface. In effect, the acid etch technique destroys the tile. In addition, the acid poses a potential safety hazard if it is not utilized properly. For a variety of reasons, some manufacturers of tile do not recommend the use of any acid cleaning on their ceramic tile products.
Other solutions to the slipperiness problem have been to lay non-slip mats upon the floor, and to apply abrasive strips to the floor. However, these mats and strips become worn rather quickly, and they hinder the daily routine cleaning of the floor. The mats sometimes come loose and slide, and they significantly alter the appearance of the floor surface. It is also is difficult to clean and sanitize the mats.
Another attempt at solving the slipperiness problem is a diamond etch technique. With the diamond etch system, a diamond cutter may be utilized to create concentric circles in the floor. The circles are approximately 1/8 to 1/4 inch in depth, which unfortunately create circular cracks for soil buildup. These circles, along with the tile's grout areas, are especially difficult to clean. It is also possible to apply a slip resistant coating to floors. These coatings can be difficult to apply, and soil can adhere to the coating.
Although sandblasting systems are known in the prior art, the typical sandblasting systems can ruin some floors and produce too much dust for indoor use. For example, the Ricklefs patent (U.S. Pat. No. 3,925,935) discloses a system for abrading the surface of a porcelain bathtub to render it slip resistant. With this system, the bottom of the tub is covered with a stencil, a cover is draped over the tub, and a stream of abrasive granules is applied to the bottom of the tub at the stencil. However, there is no teaching or disclosure in the Ricklefs patent regarding the utilization of a system for cleaning and restoring floor surfaces.
Another attempt found in the prior art is described in the Mead patent, U.S. Pat. No. 2,770,924. This patent discloses a blasting device for cleaning and treating surfaces such as wood, glass, metal, cement, or a synthetic. In addition, British Patent No. 2193454A describes a system for projecting glass beads, grit or sand onto a surface to be cleaned. With this system, the compressor and the storage container for the grit are mounted upon a truck.
The present invention addresses the problems associated with currently available cleaning techniques.